Human T cell activation. IV. T cell activation and proliferation via the early activation antigen EA 1

S. Nakamura, S. S.J. Sung, J. M. Bjorndahl, S. M. Fu

Research output: Contribution to journalArticle

64 Citations (Scopus)


A new mAb G38 was generated against purified EA 1, an early activation antigen. In immunoprecipitation, it was reactive with the same complex precipitated by the initial anti-EA 1 mAb P8. mAb G38 augmented PMA-induced proliferation of PBMC. It was shown to be mitogenic for purified T cells in collaboration with PMA in a dose-dependent manner. This effect was independent of monocytes and other accessory cells. mAb G38 augmented PMA-induced IL-2-R expression. In conjunction with PMA, it induced IL-2 synthesis and secretion. Its effects on IL-2-R and IL-2 expression were documented at both protein and mRNA levels. Both anti-EA 1 mAbs did not induce Ca2+ influx by themselves in PMA-treated T cells. However, the addition of second anti-mouse Ig antibodies induced readily detectable increases in [Ca2+](i). Ca2+-mediated pathways may be utilized as the transduction signal mechanisms. mAb Leu-23 was shown to be reactive with EA 1. mAb Leu-23 was also mitogenic for T cells in the presence of PMA. These findings provide evidence for a functional role for EA 1 in T cell activation and proliferation.

Original languageEnglish
Pages (from-to)677-689
Number of pages13
JournalJournal of Experimental Medicine
Issue number3
Publication statusPublished - Jan 1 1989
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Immunology and Allergy
  • Immunology

Cite this